J/AJ/155/44 Properties of PMS stars in young cluster Berkeley 59 (Panwar+, 2018)
Young cluster Berkeley 59: properties, evolution, and star formation.
Panwar N., Pandey A.K., Samal M.R., Battinelli P., Ogura K., Ojha D.K.,
Chen W.P., Singh H.P.
<Astron. J., 155, 44 (2018)>
=2018AJ....155...44P 2018AJ....155...44P (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Photometry, VRI ;
Stars, masses ; Stars, ages
Keywords: open clusters and associations: general - stars: formation -
stars: luminosity function, mass function - stars: pre-main sequence
Abstract:
Berkeley 59 is a nearby (∼1 kpc) young cluster associated with
the Sh2-171 H II region. We present deep optical observations of the
central ∼2.5x2.5 pc2 area of the cluster, obtained with the 3.58 m
Telescopio Nazionale Galileo. The V/(V-I) color-magnitude diagram
manifests a clear pre-main-sequence (PMS) population down to
∼0.2 M☉. Using the near-infrared and optical colors of the
low-mass PMS members, we derive a global extinction of AV=4 mag and
a mean age of ∼1.8 Myr, respectively, for the cluster. We constructed
the initial mass function and found that its global slopes in the mass
ranges of 0.2-28 M☉ and 0.2-1.5 M☉ are -1.33 and -1.23,
respectively, in good agreement with the Salpeter value in the solar
neighborhood. We looked for the radial variation of the mass function
and found that the slope is flatter in the inner region than in the
outer region, indicating mass segregation. The dynamical status of the
cluster suggests that the mass segregation is likely primordial. The
age distribution of the PMS sources reveals that the younger sources
appear to concentrate close to the inner region compared to the outer
region of the cluster, a phenomenon possibly linked to the time
evolution of star-forming clouds. Within the observed area, we derive
a total mass of ∼103 M☉ for the cluster. Comparing the
properties of Berkeley 59 with other young clusters, we suggest it
resembles more closely the Trapezium cluster.
Description:
The VI observations of the two regions of the cluster Be 59 (see Figure 1),
region "A" (RA: 00h02m14.0s, DE: +67°25'08.0"), and region "B"
(RA: 00h01m08.0s, DE: +67°33'03.0"), and a control field having
the same area (centered at RA: 00h09m48.0s, DE: +68°07'58.0") were
obtained by using the Device Optimized for the LOw RESolution (DOLORES)
instrument mounted on the 3.58 m Telescopio Nazionale Galileo (TNG).
DOLORES is a focal reducer instrument equipped with a 2048x2048 square
pixel CCD detector, with a plate scale of 0.252"/pixel and a field of view
(FoV) of 8.6'x8.6'. During the observations, the average seeing was ∼1".
Objects:
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RA (ICRS) DE Designation(s)
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00 02 14 +67 25.0 Berkeley 59 = Cl Berkeley 59
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 64 420 Magnitudes, mass and age of the PMS stars
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See also:
J/other/BASI/35.53 : JH photometry of Berkeley 59 (Sharma+, 2007)
J/MNRAS/383/1241 : UBVIc photometry of cluster Berkeley 59 (Pandey+, 2008)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/420] Internal index number
5- 12 F8.6 deg RAdeg Right Ascension in decimal degrees (J2000)
14- 22 F9.6 deg DEdeg Declination in decimal degrees (J2000)
24- 28 F5.2 mag Vmag [17.14/24.05] TNG/DOLORES apparent V band
magnitude
30- 33 F4.2 mag e_Vmag [0/0.11] Uncertainty in Vmag
35- 39 F5.2 mag Imag [14.13/19.55] TNG/DOLORES apparent I band
magnitude
41- 44 F4.2 mag e_Imag [0.01/0.21] Uncertainty in Imag
46- 49 F4.2 Msun Mass [0.16/2.24] Stellar mass
51- 54 F4.2 Msun e_Mass [0/1.07] Uncertainty in Mass
56- 59 F4.2 Myr Age [0.1/5] Stellar age
61- 64 F4.2 Myr e_Age [0/0.56] Uncertainty in Age
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 21-Sep-2018